Dual pump



Oct. 28, 1958 M. G. MCLEAN ,8

DUAL PUMP Filed March 23, 1956 lira].

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United States Patent DUAL PUMP Murray G. McLean, Burbank, Califi, assignor to Jabsco Pump Company, Burbank, Calif., a corporation of California Application March 23, 1956, Serial No. 573,383 Claims. (Cl. 103-4 The present invention relates in general to pumps and, more particularly, to pumps having impellers of the flexible radial vane type, impellers of this type being molded of rubber, or other materials having similar characteristics as to flexibility, resilience and the like. i

A primary object of the invention is to provide a dual pump of the foregoing nature having twoimpellers interconnected for rotation in unison.

More specifically, an object of the invention is to provide a pump which includes a housing having two intersecting cylindrical bores therein in side-by-side relation, which includes a cam in the housing at the intersection of the bores and having two oppositely facing cam surfaces respectively merging with the peripheral walls of the bores and cooperating therewith to provide two impeller chambers, and which includes two impellers respectively disposed in the impeller chambers and rotatable about the respective axes of. the cylindricalbores, each of the impellers having flexible vanes alternately engageable with the bore wall and the cam surface defining the impeller chamber in which it is disposed so as to produce the desired pumping action. In other words, with this construction, a single cam serves to flex the vanes of the two impellers in the two impeller chambers to provide the desired pumping actions, which is an important feature of the invention.

In the foregoing construction, the intersecting cylindrical bores provide the housing with two generally triangular apices respectively disposed on opposite sides of the intersection of the bores and facing inwardly toward each other, an important object of the invention being to provide the cam with two generally triangular recesses therein which face outwardly away from each other and which receive the respective generally triangular apices of the housing therein to key the cam to the housing. Thus, the cam is locked in place relative to the housing merely by inserting the cam into the housing from one end thereof in such a manner that the generally triangular apices on the housing are inserted into the generally triangular recesses in the cam.

Another object is to provide a pump wherein the two impellers are respectively mounted on impeller shafts which are geared together, or otherwise connected together, in such a manner that rotation of one of the shafts is transmitted to the other to rotate the two impellers in unison and in opposite directions.

' Another object of the invention is to provide the pump housing with inlet and outlet passages common to the two impeller chambers so that the inlet flow divides and enters the two impeller chambers, the fluid discharged by the two impellers entering the common outlet passage.

Another object is to provide a pump housing having inlet ports in one of the triangular apices thereof which communicate with the respective impeller chambers and which communicate with the inlet passage, the cam having inlet ports therein in register with the respective inlet ports in such triangular apex. Similarly, an object is to provide a pump housing having outlet ports in the other outlet passage, the cam having outlet ports therein whichregister with the respective outlet ports in the triangular apex in question.

Another object is to provide a dual pump of the foregoing character wherein end walls of the two impeller chambers are defined by end plates respectively inserted into the two cylindrical bores. Another object in this connection is to provide means for keying the two end plates against rotation comprising a pin carried by the housing and inserted into adjoining notches in the peripheries of the two end plates. Still another object in this connection is to provide end plates keyed together against rotation by means of interengaging flats on the peripheries thereof.

light of this disclosure, may be attained with the exemplary embodiments of the invention illustrated in the accompanying drawing and described in detail hereinafter. Referring to the drawing:

Fig. 1 is a longitudinal sectional view-of a pump which embodies the present invention;

Fig. 2 is a transverse sectional view on a reduced scale taken along the arrowed line 22 of Fig. 1;

Fig. 3 is a transverse sectional view similar to Fig. 2, but illustrating a slightly modified embodiment of the invention.

Fig. 4 is a transverse sectional view taken along the arrowed line 4-4 of Fig. 1, but corresponding to the modified embodiment of Fig. 3; and

Fig. 5 is an isometric view on a reduced scale showing a housing and a cam of the invention corresponding to the modified embodiment of Figs. 3 and 4 of the drawing.

The pump of the invention includes a pump housing 10 and a gear housing 12 rigidly connected together, as by arms 14. The pump housing10 is provided with two intersecting cylindrical bores 16 and 18 in side-by-side relation, the outer ends of these bores being closed by a cover plate 20 removably connected to the pump housing. Extending into the cylindrical bores 16 and 18 and rotatable about the axes thereof are shafts 22 and 24, seals 26 and 28 being interposed between the shafts 22 and 24 and the housing 10. The shafts 22 and 24 extend into the gear housing 12 and are rotatably mounted in bearings 34) and 32, respectively, therein, seals 34 and 36 being interposed between the shafts 22 and 24 and the gear housing 12 where they enter such housing from the pump housing Ml. Fixed on the shafts 22 and 24 are meshed gears 38 and 40 within the gear housing 12, the shaft 22 projecting through a removable cover plate 42 on the gear housing for connection to an external driving means, not shown. A seal 44 is interposed between the shaft 22 and the cover plate 42. With this construction, rotation of the shaft 22 by the external driving means in one direction results in rotation of the shaft 24 in the opposite direction due to the action of the gears 38 and 40.

Returning to the pump housing 10, the cylindrical bores 16 and 18 therein provide this housing with generally triangular apices 46 and 48 respectively disposed on opposite sides of the intersection of the bores and facing inwardly toward each other. Located in the pump housing 10 at the intersection of the bores 16 and 18 is a cam 50, this cam having therein generally triangular recesses 52 and 54 which face outwardly away from each other and which are complementary to the generally triangular apices 46 and 48, the recesses 52 and 54 respectively receiving the apices 46 and 48 therein to key the cam 50 to the pump housing 10. As best shown in Fig. 5 of the drawing, when the cover plate is removed, the came 50 may be inserted into the pump housing 10 readily in such a manner that the apices 46 and 48 fit into the respective recesses 52 and 54 in the cam to lock the cam in place, no other securing means for the cam being necessary which isan important feature of the invention.

The, cam 50 is provided with two oppositely facing cam surfaces 56 and 58 respectively merging with the peripheral walls of the cylindrical bores 16 and 18 and cooperating therewith to provide two impeller chambers 60 and 62 respectively. Disposed in the respective impeller chambers 60 and 62 and suitably keyed to the respective shafts 22 and 24 are impellers 64 and 66 of molded rubber, or the like, the impellers 64 and 66 respectively including hubs 68 and 70 respectively having flexible vanes 72 and 74 projecting radially therefrom. In the particular construction illustrated, inserts 76 and 78 are molded into the hubs 68 and 70, respectively, and are keyed to the shafts 22 and 24, respectively, by splining.

The pump housing 10 is provided with inlet and outlet passages 80 and 82 in inlet bosses 84 and 86 to which flanged inlet and outlet fittings, not shown, may be connected. The axes of the inlet and outlet passages 80 and 82 bisect the apices 46 and 48, respectively, the peripheral Walls of the bores 16 and 18 being provided with inlet ports 88 and 90 which communicate with the bores 16 and 18, respectively, and which communicate with the inlet passage 80. In the particular construction illustrated, the respective inlet ports 88 and inlet ports 90 are joined. The cam 50 is provided with notch-shaped inlet ports 92 and 94 therein which register with the inlet ports 88 and 90, respectively, to establish communication between the inlet passage 80 and the impeller chambers 60 and 62. Similarly, the peripheral walls of the bores 16 and 18 are provided with joined outlet ports 96 and 98, respectively, which communicate with the outlet passage 82 and which communicate with the interiors of the bores 16 and 18, respectively. The cam 50 is provided with notch-shaped outlet ports 100 and 102 which register with the outlet ports 96 and 98, respectively, to establish communication between the impeller chambers 60 and 62 and the outlet passage 82.

Considering the operation of the pump of the invention as thus far described, it will be assumed that the shaft 22 is rotated in the direction of the arrow 104 of Fig. 4 to rotate the impeller 64 in the same direction. Consequently, the gears 38 and 40 rotate the shaft 24 in the opposite direction to rotate the impeller 66 in the opposite direction, as indicated by the arrow 106 in Fig. 4. As the vanes 72 of the impeller 64 alternately engage the peripheral wall of the bore 16 and the cam surface 56, the spaces between the vanes 72 increase in volume adjacent the inlet ports 88 and 92 to draw fluid thereinto from the inlet passage 80, and decrease in volume adjacent the outlet ports 96 and 100 to discharge. fluid therefrom into the outlet passage 82. Similarly, as the vanes 74 of the impeller 66 alternately engage the peripheral wall of the bore 18 and the cam surface 58, the spaces between the vanes 74 increase in volume adjacent the inlet ports 90 and 94 so that fluid is drawn thereinto from the inlet passage 80, and decrease in volume adjacent the outlet ports 98 and 102 so that fluid is discharged therefrom into the outlet passage 82. Thus, the single cam 50 flexes the vanes 72 and 74 of both the impellers 64 and 66 to provide the desired pumping actions by both the impellers as they rotate in opposite directions. The fluid flow into the pump by way of the inlet passage 80 divides so that each impeller pumps substantially one-half of the fluid, the fluid discharged from the two impeller chambers 60 and 62 leaving the pump by way of the common outlet passage 82.

It will be understood that, with the particular construction illustrated wherein the cam 50 is symmetrical about a central vertical plane and wherein the inlet and outlet ports and passages are symmetrically arranged with rereversal of the directions of rotation of the impellers, the

passage 82 becomes the inlet passage and the passage becomes the outlet passage. Thus, the pump of the invention will pump in either direction, which is an important feature.

As best shown in Figs. 1, 2 and 3 of the drawing, the cylindrical bores 16 and 18 are provided with end, wear plates therein behind, the cam 50 which define the inner end walls of the impeller chambers 60 and 62, respectively, these end plates being designated by the numerals 108 and 110 in Figs. 1 and 2 of the drawing and being designated by the numerals 112 and 114 in Fig. 3 thereof. The end plates 108 and 110 are keyed to the housing 10 to prevent rotation thereof by means of a pin 116 carried by the housing and inserted into adjoining notches 118 and 120 in the peripheries of the end plates 108 and 110, respectively. The end plates 112 and 114 are keyed against rotation by providing them with interengaging flats 112 and 122, respectively. Thus, rotation of the end plates 108 and 110 relative to the housing 10 and rotation of the end .plates 112 and 114 relative thereto are prevented very simply, which is a feature of the invention.

Although I have disclosed exemplary embodiments of my. invention herein for purposes of illustration, it will be understood that various changes, modifications and-substitutions may be incorporated in such embodiments without departing from the spirit of the invention as defined by the claims hereinafter appearing.

I claim as my invention:

1. In a pump, the combination of: a housing provided with two cylindrical bores therein in side-by-side relation; a cam in said housing between said bores and provided with two oppositely facing cam surfaces respectively merging with the peripheral walls of said bores and cooperating therewith to provide two impeller chambers one defined by one of said peripheral walls and one of said cam surfaces and the other defined by the other of said peripheral walls and the other of said cam surfaces, said cam surfaces being nearer the axes of said bores, respectively, than said peripheral walls of said bores, respectively; two impellers respectively disposed in said impeller chambers and rotatable about the respective axes of said bores, said impellers having circumferentially spaced, bendable vanes respectively alternately engageable with said peripheral walls and said cam surfaces defining said impeller chambers as said impellers rotate therein, whereby said vanes of said impellers bend as they respectively engage said cam surfaces of said impeller chambers so as to decrease the volumes of the spaces between said vanes of said impellers in first zones of said impeller chambers, respectively, and whereby said vanes of said impellers unbend as they respectively disengage said cam surfaces of said impeller chambers so as to increase the volumes of the spaces between said vanes of said impellers in second zones of said impeller chambers, respectively, circumferentially spaced from said first zones thereof; and inlet and outlet ports in said housing and respectively communicating with said second and first zones of said impeller chambers.

2. A pump as defined in claim 1 wherein said cam is a separate element and is removable from said housing, said pump including interengaging means on said housing and said cam for securing said cam in said housing.

3. In a pump, the combination of a housing provided with two intersecting cylindrical bores therein in sideby-side relation, said bores providing said housing with generally triangular apices respectively disposed on opposite sides of the intersection of said bores and facing inwardly toward each other; a cam in said housing at 7 said intersection and having generally triangular recesses therein which face outwardly away from each other and which receive said apices therein, respectively, to key said cam to said housing, said cam having two oppositely facing cam surfaces respectively merging with the peripheral walls of said bores and cooperating therewith to provide two impeller chambers one defined by one of said peripheral walls and one of said cam surfaces and the other defined by the other of said peripheral walls and the other of said cam surfaces, said cam surfaces being nearer the axes of said bores, respectively, than said peripheral walls of said bores, respectively; two impellers respectively disposed in said impeller chambers and rotatable about the respective axes of said bores, said impellers having circumferentially spaced, bendable vanes respectively alternately engageable with said peripheral walls and said cam surfaces defining said impeller chambers as said impellers rotate therein, whereby said vanes of said impellers bend as they respectively engage said cam surfaces of said impeller chambers so as to decrease the volumes of the spaces between said vanes of said impellers in first zones of said impeller chambers, respectively, and whereby said vanes of said impellers unbend as they respectively disengage said cam surfaces of said impeller chambers so as to increase the volumes of the spaces between said vanes of said impellers in second zones of said impeller chambers, respectively, circumferentially spaced from said first zones thereof; and inlet and outlet ports in said housing and respectively communicating with said second and first zones of said impeller chambers,

4. In a pump, the combination of: a housing provided with two intersecting cylindrical bores therein in sideby-side relation, said bores providing said housing with generally triangular apices respectively disposed on opposite sides of the intersection of said bores and facing inwardly toward each other; a cam in said housing at said intersection and having generally triangular recesses therein which face outwardly away from each other and which receive said apices therein, respectively, to key said cam to said housing, said cam having two oppositely facing cam surfaces respectively merging with the peripheral walls of said bores and cooperating therewith to provide two impeller chambers one defined by one of said peripheral walls and one of said cam surfaces and the other defined by the other of said peripheral walls and the other of said cam surfaces, said cam surfaces being nearer the axes of said bores, respectively, than said peripheral walls of said bores, respectively; two shafts rotatable relative to said housing and extending into said impeller chambers, respectively, the axes of said shafts coinciding with the axes of said bores, respectively; means interconnecting said shafts for transmitting rotation of one of said shafts to the other; two impellers respectively disposed in said impeller chambers and respectively mounted on said shafts, said impellers having circumferentially spaced, bendable vanes respectively alternately engageable with said peripheral walls and said cam surfaces defining said impeller chambers as said impellers rotate therein, whereby said vanes of said impellers bend as they respectively engage said cam surfaces of said impeller chambers so as to decrease the volumes of the spaces between said vanes of said impellers in first zones of said impeller chambers, respectively, and whereby said vanes of said impellers unbend as they respectively disengage said cam surfaces of said impeller chambers so as to increase the volumes of the spaces between said vanes of said impellers in second zones of said impeller chambers, respectively, circumferentially spaced from said first zones thereof; and inlet and outlet ports in said housing and respectively communicating with said second and first zones of said impeller chambers.

5. A pump according to claim 3 wherein there are two of said inlet ports and two of said outlet ports, said housing being provided with an inlet passage and said inlet ports being formed in one of said apices and communicating with said inlet passage, said cam being provided with inlet openings therein which register with said inlet ports in said one apex, respectively, and which register with said second zones, respectively, said housing having an outlet passage and having said outlet ports in the other of said apices, said outlet ports communicating with said outlet passage, said cam having therein outlet openings which register with said outlet ports in said other apex, respectively, and which register with said first zones, respectively.

6. A pump as defined in claim 3 including two end plates respectively disposed in said bores and respectively defining end walls of said impeller chambers, said pump including means for keying said end plates together.

7. A pump according to claim 6 wherein said keying means includes a pin carried by said housing and extending into notches in the peripheries of said end plates, respectively.

8. A pump according to claim 6 wherein said keying means includes interengaging flats on the peripheries of said end plates.

9. In a pump, the combination of: a housing provided with two impeller chambers therein in side-by-side relation, each of said impeller chambers including a peripheral cylindrical section and a peripheral cam section, said cam sections being adjacent each other and facing away from each other and being nearer the axes of said peripheral cylindrical sections, respectively, than said peripheral cylindrical sections; two impellers respectively disposed in said impeller chambers and rotatable about the respective axes of said peripheral cylindrical sections thereof, said impellers having circumferentially spaced, bendable vanes respectively alternately engageable with said peripheral cylindrical sections and said peripheral cam sections defining said impeller chambers as said impellers rotate therein, whereby said vanes of said impellers bend as they respectively engage said cam sections of said impeller chambers so as to decrease the volumes of the spaces between said vanes of said impellers in first zones of said impeller chambers, respectively, and whereby said vanes of said impellers unbend as they respectively disengage said cam sections of said impeller chambers so as to increase the volumes of the spaces between said vanes of said impellers in second zones of said impeller chambers, respectively, circumferentially spaced from said first zones thereof; and inlet and outlet ports in said housing and respectively communicating with said second and first zones of said impeller chambers.

10. In combination: a housing provided with two chambers therein in side-by-side relation, said housing having an opening which connects said chambers and which extends lengthwise thereof, said housing having projections respectively disposed on opposite sides of said opening and extending lengthwise of said chambers and facing inwardly toward each other; and a member in said housing and filling said opening and having recesses in opposite sides thereof which face outwardly away from each other and which receive said projections therein, respectively, to key said member to said housing.

References Cited in the file of this patent UNITED STATES PATENTS 709,597 Frank Sept. 23, 1902 1,296,500 Frodsham Mar. 4, 1919 1,476,482 Berrenberg Dec. 4, 1923 2,372,480 Fuchs Mar. 27, 1945 2,487,721 Minshall Nov. 8, 1949 2,499,163 Rand Feb. 2 3, 1950 2,719,001 Knuth Sept. 27, 1955 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION I Patont No, 2,857,848 Ooaobor 28, 1958 Murray G o McLean It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Colwnn 3,, line 2, for "came 50" read. N @am 5O 5 "inlet" insert and outlet Signed and sealed this 27th day of January 19590 7 SEAL) Attest:

KARL Ha AXLINE ROBERT C. WATSON Attesting Oflicer Commissioner of Patents 

